結果

問題 No.20 砂漠のオアシス
コンテスト
ユーザー t8m8⛄️
提出日時 2015-04-12 15:06:34
言語 Java
(openjdk 23)
結果
AC  
実行時間 918 ms / 5,000 ms
コード長 5,315 bytes
コンパイル時間 5,163 ms
コンパイル使用メモリ 80,220 KB
実行使用メモリ 45,704 KB
最終ジャッジ日時 2024-10-13 05:06:03
合計ジャッジ時間 7,417 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge3
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ファイルパターン 結果
other AC * 21
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ソースコード

diff # 

//No.20 砂漠のオアシス

import java.util.*;
import java.io.*;
import static java.util.Arrays.*;
import static java.lang.Math.*;

public class No20_2 {

    static final Reader in = new Reader();
    static final PrintWriter out = new PrintWriter(System.out,false);

    static void solve(){
        int n = in.nextInt();
        int v = in.nextInt();
        int ox = in.nextInt()-1;
        int oy = in.nextInt()-1;

        int[][] l = new int[n][n];
        for (int i=0; i<n; i++) l[i] = in.nextIntArray(n);


        int[] d = dijkstra(l,0);
        if (ox == -1 && oy == -1) {
            out.println(d[(n-1)*n+(n-1)] < v ? "YES" : "NO");
        }else {
            int[] d2 = dijkstra(l,oy*n+ox);
            out.println(d[(n-1)*n+(n-1)] < v || d2[(n-1)*n+(n-1)] < 2*(v-d[oy*n+ox]) ? "YES" : "NO");
        }
    }

    static int[] dijkstra(int[][] table, int from) {
        int[] dy = {0,0,1,-1};
        int[] dx = {1,-1,0,0};

        int h = table.length, w = table[0].length;
        final int[] d = new int[h*w];
        Arrays.fill(d,Integer.MAX_VALUE/2);
        PriorityQueue<Integer> que = new PriorityQueue<Integer>(new Comparator<Integer>(){
            public int compare(Integer a, Integer b) {
                if (d[a] != d[b]) return d[a] - d[b];
                return a - b;
            }
        });

        que.add(from);
        d[from] = 0;
        while (!que.isEmpty()) {
            int cur = que.poll();
            int y = cur/w, x = cur%w;

            for (int i=0; i<4; i++) {
                int ny = y + dy[i];
                int nx = x + dx[i];
                if (nx < 0 || w <= nx || ny < 0 || h <= ny) continue;

                if (d[cur] + table[ny][nx] < d[ny*w+nx]) {
                    d[ny*w+nx] = d[cur] + table[ny][nx];
                    que.remove(ny*w+nx);
                    que.add(ny*w+nx);
                }
            }
        }

        return d;
    }

    public static void main(String[] args) throws Exception {
        long start = System.currentTimeMillis();

        solve();
        out.flush();

        long end = System.currentTimeMillis();
        //trace(end-start + "ms");
        in.close();
        out.close();
    }

    static void trace(Object... o) { System.out.println(deepToString(o));}
}

class Reader {
    private final InputStream in;
    private final byte[] buf = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;

    public Reader() { this(System.in);}
    public Reader(InputStream source) { this.in = source;}

    private boolean hasNextByte() {
        if (ptr < buflen) return true;
        ptr = 0;
        try{
            buflen = in.read(buf);
        }catch (IOException e) {e.printStackTrace();}
        if (buflen <= 0) return false;
        return true;
    }

    private int readByte() { if (hasNextByte()) return buf[ptr++]; else return -1;}

    private boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}

    private void skip() { while(hasNextByte() && !isPrintableChar(buf[ptr])) ptr++;}

    public boolean hasNext() {skip(); return hasNextByte();}

    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        boolean minus = false;
        long num = readByte();

        if(num == '-'){
            num = 0;
            minus = true;
        }else if (num < '0' || '9' < num){
            throw new NumberFormatException();
        }else{
            num -= '0';
        }
        
        while(true){
            int b = readByte();
            if('0' <= b && b <= '9')
                num = num * 10 + (b - '0');
            else if(b == -1 || !isPrintableChar(b))
                return minus ? -num : num;
            else
                throw new NoSuchElementException();
        }
    }

    public int nextInt() {
        long num = nextLong();
        if (num < Integer.MIN_VALUE || Integer.MAX_VALUE < num)
            throw new NumberFormatException();
        return (int)num;
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }

    public char nextChar() {
        if (!hasNext()) throw new NoSuchElementException();
        return (char)readByte();
    }

    public String nextLine() {
        while (hasNextByte() && (buf[ptr] == '\n' || buf[ptr] == '\r')) ptr++;
        if (!hasNextByte()) throw new NoSuchElementException();

        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while (b != '\n' && b != '\r') {
            sb.appendCodePoint(b);
            b = readByte();
        }

        return sb.toString();
    }

    public int[] nextIntArray(int n) {
        int[] res = new int[n];
        for (int i=0; i<n; i++) res[i] = nextInt();
        return res;
    }

    public char[] nextCharArray(int n) {
        char[] res = new char[n];
        for (int i=0; i<n; i++) res[i] = nextChar();
        return res;
    }

    public void close() {try{ in.close();}catch(IOException e){ e.printStackTrace();}};
}
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